


By the Sea

by mimsyborogove



Category: The Infernal Devices Series - Cassandra Clare, The Mortal Instruments Series - Cassandra Clare, The Shadowhunter Chronicles - All Media Types, The Shadowhunter Chronicles - Cassandra Clare
Genre: F/F, mermaid au
Language: English
Status: Completed
Published: 2020-01-04
Updated: 2020-01-04
Packaged: 2021-02-27 15:34:00
Rating: Teen And Up Audiences
Warnings: No Archive Warnings Apply
Chapters: 1
Words: 4,592
Publisher: archiveofourown.org
Story URL: https://archiveofourown.org/works/22079272
Author URL: https://archiveofourown.org/users/mimsyborogove/pseuds/mimsyborogove
Summary: “Are you there?” Tessa called out to the waves, feeling ridiculous. Maybe she had dreamed the whole thing after all. It was absurd, wasn’t it? The idea that something from the sea had saved her from drowning.“Hello?” she called again. It was absurd, but she had to be sure.“Not many people return so quickly to the spot where they almost died,” a soft voice said from below her. “You’re either very brave, or very foolish.Tessa jumped. Even though she had been watching, she hadn’t seen anyone approach. She looked down by her feet and saw the face of a beautiful woman poking out of the water. Her skin was blue, nearly blending into the water, long braids of white hair floating around her like sea foam.“You’re the one who saved me,” Tessa breathed out, barely daring to believe this was real.The woman nodded, the movement making the array of pearls wound into her hair nearly glow in the morning light.“But you aren’t human.” She couldn’t be. Not with skin that color.The woman laughed at that, twisting so the end of a shimmering sapphire blue fish tail rose out of the water. “No, I’m not.”“A mermaid,” Tessa murmured in awe. “I thought mermaids only existed in stories.”
Relationships: Tessa Gray/Catarina Loss
Comments: 4
Kudos: 26





	By the Sea

Tessa Gray put one foot in front of the other on the cobblestone road, taking no notice of where those feet were taking her. Her mind felt foggy, a deep ache of grief settling into her chest now that the funeral was over and there were no more tasks to keep her busy or distract her from her sadness. 

Nate had abandoned her to make her own way home as soon as the service was over, and none of the acquaintances who had come to see Aunt Harriet to rest had stayed to offer any comfort either. 

Tessa assumed she was going home—that was where she had intended to go after the funeral—but when she finally took notice of her surroundings, she found herself walking down to the beach, straight for the tiny path that led to her secret cove. 

She considered the cove hers at least. She had never seen another person there, and the single path that led to it vanished when the tide was high, so she suspected she was the only one in town who knew of it. And as long as she was careful with her timing, she could always get out before the tide covered the path too deeply for her to be able to walk back to the main beach. 

She always felt better when she was by the water, though she didn’t know how to swim. Aunt Harriet had considered it improper for girls to learn. But just sitting by the water where she could hear the waves made her feel safer, more grounded somehow. 

Tessa had been a sickly baby, according to her aunt. Her parents had moved their family to this seaside town for her health when she was small, thinking the sea air would do her good. But they had been killed in a boating accident shortly after, and Aunt Harriet had come to take care of Tessa and Nate.

But Aunt Harriet had always hated it here, and had always forbid Tessa from going near the water.

She would have been furious if she had ever discovered Tessa sneaking down to sit by the beach and read, but Tessa couldn’t help it. Despite her best efforts, she still always found herself drawn to the sea, though she never dared to do more than take off her shoes and stockings and let her feet dangle off the rocks into the cool comfort of the water.

Her cove was really just a tiny indention in the rocky hills that made up most of the shore, but it was quiet and there were rocks worn smooth enough for her to sit comfortably while she read a book. It was an escape from the stifling life in their tiny house, and that was all that Tessa needed.

She didn’t have a book today, so she sat down on her favorite rock—the one that was nearly completely flat and large enough for her to lay on if she had wanted to—and stared out at the water. The sky was dull and overcast. It almost felt like it was reflecting the complete lack of color she felt inside.

What were they going to do without Aunt Harriet? Nate could barely hold down his job at the docks, and he lost most of what he earned gambling. Tessa made a little money teaching some of the local children how to read, but it wasn’t enough for both of them to live on, and Nate was libel to take that if he found it too. 

The past two weeks of taking care of Aunt Harriet while the fever raged, then moved into a cough that wouldn’t get better before she had finally passed in the dark hours of yesterday morning while Nate had still been out drinking had left Tessa mentally and physically exhausted.

She closed her eyes for a moment to gather herself. She would go back to the house and figure out what she could sell to make ends meet until she found some other way for her and Nate to make it on their own. She just needed to rest her eyes. Just for a minute.

A splash of water against her leg startled her awake, and she jerked back from the edge of the rock. The cove didn’t usually flood completely, even if the path to it did. Not unless there was a— 

Tessa looked up in horror just as a flash of lightning ripped across the sky, followed by a rumble of thunder loud enough to rattle the rocks around her. 

_Oh no._

How long had she been asleep? How had she not noticed a storm was brewing? The waves were already too strong for her to find her footing on the path, even if it was still shallow enough for her to keep her head above the water. 

But she had to try. There was no other way out, and every second she waited made it more impossible that she could make it to safety. 

She was soaked through in moments, her wet dress weighing her down as she tried to pick her way back across the rocks. Another wave hit, this time knocking her feet out from under her completely. 

Tessa’s scream was cut off by the mouthful of seawater she choked on. She tried to cough, to call for help, but only breathed in more water as she tried to keep herself from sinking. If she could just make it back to the rocks. But where were the rocks? She looked around frantically. The tide was already carrying her out to deeper water. 

Something wrapped around her from behind, right under her arms and around her shoulders, pinning her down and restricting the movement of her arms. 

“It’s all right,” a soft voice murmured in her ear. “I’ve got you. I’ll get you back to shore, but I need you to stop struggling.”

Tessa fought against every instinct to claw at the arms around her—for that’s what they were somehow, arms in the ocean in the middle of the storm—in a mad attempt to use her rescuer as an impossible means to try to climb out of the water. She forced her body go slack, and surprisingly, her head stayed above water. 

“Just like that,” the gentle voice reassured her. “I won’t let you drown.”

Tessa felt herself being towed backwards, back towards the larger beach she would be able to walk home from. 

The water got shallower, and once she could reach the bottom, the arms around her loosened, supporting her as she shakily stood in the waves rather than holding her up completely. 

“Can you make it the rest of the way?” the voice asked. “This is as far as I can carry you.”

Tessa coughed as she nodded, her breaths not yet coming easily enough to speak, but her legs were steady enough now to stagger back to the safety of the shore. 

She turned to thank her rescuer, and ask what on earth she was doing swimming in the ocean in the middle of a storm, but there was no one standing next to her. She was alone on the beach. 

She spun around, back toward the sea and caught a flash of white and the silhouette of a hand that nearly blended into the color of the water waving goodbye before the figure vanished into the waves.

Tessa walked home through the downpour in a daze. She didn’t bother to hurry to get out of the rain. It wasn’t like she could get any wetter. Nate was still gone when she got home, so she didn’t even have to explain herself to anyone. 

She peeled off her sodden clothes, carelessly draping her dress over the back of a chair, and changed into her dry nightgown before sliding into the soft safety of her bed. 

She should be as dead as Aunt Harriet, carried out to sea like that, she thought, staring up at the ceiling like the answers might be written there.

Who—or _what_ —had saved her?

——

Tessa woke early the next morning, the bright sunrise promising a clear day in the wake of yesterday’s storm. She sat straight up in the bed. The storm. She had been caught in it and swept out to sea, hadn’t she? Or had it been a nightmare in the wake of her aunt’s funeral?

She scrambled out of bed and picked up the dress she had worn yesterday. Still damp.

Nate was still sleeping off his night of drinking, and Tessa didn’t expect him to wake for hours yet. She slipped out of the house unnoticed. She was sure she would be back in time to have breakfast—or more likely lunch—ready for Nate by the time she had to wake him for his shift at the dock. 

She made her way back to her cove. The tide was low now, and the path there was easy as long as you knew where to step. Tessa stood on her flat rock, searching the deep blue water for any sign of movement under the rippling surface. 

“Are you there?” Tessa called out to the waves, feeling ridiculous. Maybe she had dreamed the whole thing after all. It was absurd, wasn’t it? The idea that something from the sea had saved her from drowning.

“Hello?” she called again. It was absurd, but she had to be sure.

“Not many people return so quickly to the spot where they almost died,” a soft, amused voice said from below her. “You’re either very brave, or very foolish.

Tessa jumped. Even though she had been watching, she hadn’t seen anyone approach. She looked down by her feet and saw the face of a beautiful woman poking out of the water. Her skin was blue, nearly blending into the water, long braids of white hair floating around her like sea foam. 

“You’re the one who saved me,” Tessa breathed out, barely daring to believe this was real. 

The woman nodded, the movement making the array of pearls wound into her hair nearly glow in the morning light. 

“But you aren’t human.” She couldn’t be. Not with skin that color. 

The woman laughed at that, twisting so the end of a shimmering sapphire blue fish tail rose out of the water. “No, I’m not.”

“A mermaid,” Tessa murmured in awe. “I thought mermaids only existed in stories.”

“Many stories contain a tiny bit of truth. The truth is what makes them linger,” the mermaid said. “Do you like stories then?”

“Oh yes,” Tessa said. “Reading is my favorite thing to do.”

Reading was the only escape she had from this lonely life, she didn’t say. 

“Tell me a story then,” the mermaid said, crossing her arms over one of the rocks and resting her head on her arms, watching Tessa expectantly.

Tessa sat down on the rock next to the mermaid, heart pounding. What did you do when a creature you didn’t think was real until just now asked you for a story? 

Would _The Little Mermaid_ be in bad taste? Tessa was having a hard time thinking of anything else under the circumstances. But a story that ended in a mermaid dying and turning into sea foam seemed rather inappropriate.

She settled on a different fairy tale, _Cinderella_ , about the poor girl who wished to escape her cruel family and was finally given the means to do so.

“An interesting choice,” the mermaid said, when Tessa had finished the story, giving Tessa a contemplative look with her deeply blue eyes. 

“Do you have a name?” Tessa asked. She was dying to know everything about this impossible creature who had saved her, and equally as fearful of saying something wrong that would make her vanish into the waves forever. 

“Catarina,” the mermaid replied.

“I’m Tessa. Tessa Gray.”

Catarina shifted, and in one powerfully elegant movement had lifted herself onto the rock to sit next to Tessa, the sun sparkling off the sapphire scales of her tail like it really was made of tiny gemstones. 

Tessa turned to find the strangely lovely face very near hers. She was smaller than Tessa had first thought. Sitting beside Tessa like this, the top of her head was about level with Tessa’s nose, though Tessa was admittedly unusually tall for a woman.

The next thing Tessa noticed was that Catarina wore nothing except for the iridescent rainbow of pearls wound about her neck and wrists and braided into her hair. Tessa’s face flushed and Catarina laughed, the sound light and musical over the steady roar of the waves. 

“Oh, I had forgotten how strange you humans were with your modesty!” Catarina laughed again as she arranged her hair over her shoulders to cover the swell of her breasts, but Tessa could still see the distracting curve of her waist where the soft blue skin of her torso blended smoothly into the darker scales of her tail.

“It has been a very long time since I’ve let a human see more than a glimpse of me as I pulled them from the waves,” Catarina continued. “But there is something different about you, Tessa Gray. You do not belong here. Not completely.”

That shocked Tessa back from her distraction. “What do you mean?”

Catarina tilted her head, considering. “I’m not entirely sure. But there’s something.”

Tessa glanced at the sun, alarmed to find how high it had risen while she had been talking. “I have to go before my brother notices I’m gone,” she said frantically. “Do you live here? Will I see you again?”

_Please say I’ll see you again_ , she thought. 

“This isn’t my home, but I’ll stay for a while,” the mermaid smiled, sliding back off the rock and sinking into the water. “Come back tomorrow and tell me another story, Tessa Gray.”

——

It was well past noon by the time Tessa made it home. She cooked lunch quickly, her stomach loudly reminding her that she had skipped breakfast that morning, before going to wake Nate. 

“Mr. Mortmain gave me the week off,” Nate mumbled into his pillow. “On account of Aunt Harriet dying. I don’t go back until Monday.”

Tessa frowned as Nate began snoring again. Mr. Mortmain owned the docks where Nate worked. Tessa had thought it unusually generous for him to give Nate the morning after the funeral off, let alone an entire week. Mortmain had a reputation for being a hard man, not the type who would give his lowest employees much sympathy for a family death.

But then again, Tessa had never met the man, so maybe he had a softer side that she didn’t know about. She shrugged it off. Stranger things had happened this week. 

She had met a _mermaid_. And Catarina had promised to wait for her again tomorrow. She’d make sure to bring a book with her tomorrow so she wouldn’t have to rely on her memory for a story to tell the mermaid. 

Tessa grinned into her cup of tea, almost giddy at the thrill of it. 

——

Tessa snuck down to the cove early every morning, and Catarina was always waiting for her, appearing moments after Tessa settled down to sit on the flat rock with her feet dangling in the water. 

Catarina had stayed mostly in the water the first fews days, but she had slowly progressed from resting her head on her arms on the rock, to sitting next to Tessa, to laying with her head in Tessa’s lap, sunning herself and lazily kicking her tail while Tessa read to her from a book of fairy tales she had brought with her, which seemed to amuse Catarina, who knew how real magic worked. 

Catarina closed her eyes contentedly while Tessa twisted small braids of her pearl-studded white hair around her fingers. “I thought it was unicorns who were supposed to lay their heads in maiden’s laps,” Tessa said.

Catarina laughed softly and opened her eyes, the irises just barely lighter than her pupils, which were a deep blue rather than black like a human’s eye. “Who wouldn’t take the chance to lay their head in a pretty girl’s lap? You’re warm and you smell so nice.”

Tessa flushed, and distracted herself again with Catarina’s hair, counting all the different colors of pearls. White, gold, pink, black, gray, green, blue. “Did you find all the pearls yourself?” she asked. “I didn’t even know they came in so many colors.” 

“Some of them,” Catarina answered. “I have a friend who is much better at it than I am though. He’s always had an eye for shiny things and a knack for picking the oysters with the nicest pearls. Most of them were gifts from him.”

_Him?_ Did Catarina have a lover? Tessa’s heart sank at the thought, though she knew it shouldn’t surprise her that someone like Catarina wasn’t as alone in the world as Tessa felt.

Catarina sat up and unwound a rope of gray pearls from around her neck, then reached up to loop it around Tessa’s. 

“They suit you,” she murmured, pushing a stray lock of hair behind Tessa’s ear. “You should keep them. They match your eyes.”

Tessa ran a finger over the smooth silvery pearls, admiring how they shone in the sunlight. “I can’t,” she sighed, taking the necklace off and reluctantly pressing it back into Catarina’s hands. “If my brother saw it, he’d take it for gambling money.”

Catarina frowned. “Why do you stay? You aren’t happy here.”

“He’s my brother,” Tessa said helplessly. “I can’t just abandon him.”

“Would he say the same of you?”

Tessa sighed again. “I don’t know,” she said. That was a hard truth she’d never been able to fully admit to herself. Nate would never take care of her the way she and Aunt Harriet had always taken care of him. “Where would I even go?”

“Come with me,” Catarina said, taking one of Tessa’s hands, lacing her blue fingers with Tessa’s pale ones. “Before winter gets too close, I’ll have to move to warmer waters. We could go together.”

Tessa’s blood froze in her veins, like the winter was already upon them, though they were just barely at the end of summer and the sun still shone warmly down on their rock. “You’re leaving?”

Catarina cupped Tessa’s cheek and gave her a small smile, but there was a trace of sadness in her eyes. “Yes. But not yet. And not forever.”

Tessa couldn’t stand the thought of Catarina leaving. Her heart couldn’t take it. Without thinking, Tessa leaned closer, closing the little bit of space between them to press her lips against Catarina’s, stopping the conversation. 

Catarina made a small surprised noise and wound her fingers into Tessa’s hair, holding her in place and tilting her head to deepen the kiss. 

Warmth flooded through Tessa as Catarina’s soft lips moved against hers, melting the ice of worry. Tessa wasn’t entirely sure what she was doing—she had never kissed anyone before—but Catarina seemed to have no problem leading her.

They kissed for a long time, Catarina’s fingers running through Tessa’s hair, sending shivers all the way down her spine, building a pool of warmth low in her stomach. 

Tessa shouldn’t be doing this, she thought. Aunt Harriet had raised her to be a proper lady in manner, though they had always been poor, and lying down on a rock by the sea while a beautiful mermaid placed small kisses behind her ear and down her neck had to be as improper as it was possible to get.

Tessa pulled Catarina closer and held tight to her anyway, the only bright spot she had in the dreary world.

——

Tessa couldn’t stop smiling on her way home that evening. It was a lot later than she usually returned. She and Catarina had both dozed off in the shade of the rocks, and after a final kiss that had lasted dangerously long, Tessa had just barely made it back to the beach before the tide got too high to see the path out of the cove. 

“Tessie, where have you been?” Nate demanded as soon as she walked in the door, wiping the smile from her face completely. She was late, but surely she wasn’t _that_ late. 

“Never mind,” he said dismissively, before she could come up with something other than ‘sleeping with beautiful mermaids’ to excuse herself. “I have wonderful news for you!” he grabbed her hands and spun her around the kitchen. “The answer to all our problems! We’ll never have to worry about money again!”

_Oh, Nate, what have you done this time,_ she wondered.

“It seems Mr. Mortmain has been getting lonely and wishes to settle down with a wife. He saw you at Aunt Harriet’s funeral, and fell for you at once, but he had to attend to some business matters before he could propose. He’s agreed to forgive all my debts for your hand in marriage. Isn’t that the most fantastic news!” Nate beamed. 

“No,” Tessa whispered, horrified, pulling her hands out of Nate’s. She couldn’t imagine anything worse than being bound to someone of her brother’s choosing, even if she hadn’t just given her heart away so completely to someone else. “Nate, I won’t marry him.”

Nate’s smile faded, replaced by annoyance. “Why ever not?” he asked. “It’s the solution to all our problems.”

“To _your_ problems, Nate, not mine. I won’t marry some old man I don’t love just to get you out of the hole you’ve gambled yourself into!”

“You don’t have a choice, Tessie. I’ve already told him you would be delighted. The wedding is set for next week.”

_‘Come with me’,_ Catarina’s sweet voice echoed in her memory. ‘ _We could go together.’_

This was it. This was the excuse Tessa needed to break away from Nate. She didn’t know _how_ she would go with Catarina yet, but they would figure it out. If they were together they could figure it out.

“I’ve already said no,” Tessa said, brushing past Nate to her bedroom, hastily gathering her belongings. Books, clothes, a few hairpins and a necklace that had been her mother’s, that even Nate was too sentimental about to gamble away. She was leaving. Right now.

“And I said you don’t have a choice,” Nate loomed in the doorway. Tessa didn’t notice the heavy jug in his hand until it was too late and he was already swinging it at her head. 

Then everything went black. 

——

“Thank you for coming, Doctor,” Nate’s voice floated through the dark. “My sister isn’t usually like this. She was thrilled when I told her about Mr. Mortmain’s proposal. I don’t know what possessed her to try to run away.”

“Hysteria,” a vaguely familiar voice replied. “It can be quite frighting to witness, especially when one thinks his own women are sensible enough to not succumb to such fits. Luckily she only suffered a mild concussion when she fell and hit her head.”

“Do you think she’s likely to be overcome by such an attack again?”

“Women are delicate creatures, and you both did recently lose your aunt. Grief and wedding nerves are the most likely problem. I’ll leave a tonic for you to give her. It should keep her docile until her fiancé returns to claim her, and things should calm down once she’s safely married.”

Something bitter pressed against Tessa’s lips, and the darkness pulled her under again. 

Tessa wasn’t sure how much time passed, fading in and out of the darkness. Sometimes she heard voices, usually Nate’s, but it was hard to make out what they were saying. 

The darkness waned again. There was a new voice this time, a woman. Tessa strained against the fog in her mind to make out the words. 

“I’m the nurse Mr. Mortmain has sent to look after Miss Gray until his return tomorrow.”

“No one told me he was sending a nurse,” Nate said.

“Maybe it slipped your mind?” the nurse soothed. “It can be quite stressful to care for an ill loved one. You should take a walk and get some fresh air. A drink, perhaps. I assure you Miss Gray will be perfectly safe in my care.”

The sound of a door opening and then closing. Tessa struggled to open her eyes, blinking blearily at the face now hovering over her. The woman was a stranger with dark skin, her black hair tucked neatly into a nurses’ cap. 

“Drink this,” she murmured, pressing something that tasted sharp and salty to Tessa’s lips. “It should counteract whatever they’ve been drugging you with.”

Tessa’s mind began to clear, and the face above her came into proper focus. Her eyes were a dark brown, but Tessa recognized the light in them, recognized the elegant curve of her cheeks, recognized the full lips she had spent so long kissing just days ago. 

_“_ Catarina,” Tessa breathed out in wonder.

Catarina smiled. “You didn’t think I would abandon you, did you?”

“But _how_?” Tessa looked down to confirm that Catarina did indeed have two legs under her respectable dress and apron, not a fish tail.

“Some friends helped me with a spell,” Catarina said. “There will be more time to explain later. We have to go before your brother returns.”

Hand in hand they crept out of the house, half expecting Nate to pop out from anywhere. When they were clear of the yard, they broke out into a run, Catarina leading Tessa along the path back to their cove. 

“If they send out a search party, they’re sure to find us here,” Tessa panted. “There’s nowhere to run.”

“We aren’t _running_ ,” Catarina said, sitting down on their rock, and drawing Tessa down beside her. She pulled a necklace out from the collar of her dress and over her head, sighing in relief as her skin faded back to blue and her legs bound themselves together in a glitter of scales. 

She held the necklace out to Tessa. Tessa recognized the gray pearls as the ones Catarina had tried to give her the last time they met, the gift Tessa hadn’t been able to accept. 

“It’s the second part of the spell,” Catarina explained. “My friends helped me enchant them while I searched for you. The spell might not work if you’re fully human, but I don’t think you _are_. I think you have some mermaid blood in your ancestry somehow, though your brother doesn’t seem to.”

“But I can’t swim,” Tessa said, heart pounding as she took the necklace, afraid of what this little bit of hope could mean. 

“I’ll teach you,” Catarina reassured her, brushing the back of her fingers against Tessa’s cheek. “I would never let you drown.”

Tessa took a deep breath and pulled the pearls over her head. The change was nearly instantaneous, her legs gone, replaced by a tail covered in silver scales. She stared down at it in wonder, experimentally kicking the water and setting of a much larger splash that she had intended.

Catarina laughed and pulled Tessa in for a kiss, the curve of Catarina’s smile against her lips setting her heart aflutter. 

“Are you ready?” Catarina asked.

Tessa nodded.

They shook themselves free of their human clothes, and Catarina smiled brightly again, holding out a hand to Tessa. Tessa took it and together they slid into the ocean. 

Tessa took a breath of water instead of air, and for the first time in her life, she felt free. 


End file.
